1. Field of the Disclosure
The present invention relates to a power ramp for a vehicle and a control method thereof. More particularly, the present invention relates to a power ramp having a main ramp movable more efficiently by both of a pair of chains and a motor assembly, which is manual-operable and overload determinable to enhance safety and durability.
2. Discussion of the Related Art
In general, vehicles have to be higher than roads and it is difficult to introduce vehicles for disables such as wheelchairs movable along the roads into large vehicles such as buses.
To introduce such a wheelchair into such a bus smoothly, various ramps having predetermined oblique have been presented to compensate the height difference between the wheelchair and bus.
Also, to improve convenience for the old and feeble to get into or out of the bus, demands for ultra-low floor buses designed with the minimum ground clearance that is below 400 mm are increasing recently. Because of that, a sliding ramp extractable to the road from a bottom of the bus to allow a wheelchair to get into the bus is installed in such an ultra-low floor bus.
However, such the various ramps would have weak durability. If load is applied to a right or left portion of such the ramp intensively, not to an overall portion uniformly, there might be twist in a bottom of the ramp that causes sliding failure.
In addition, if the sliding of the ramp is not preformed by an obstacle, there might be damage to a motor or the ramp.
Furthermore, if the ramp is operated, with not identifying a state of the vehicle parking and a state of a door open or closed, there might be an accident that occurs because of vehicle movement or collision with the door.